Awk Part 11

Gnu Awk Documentation: https://www.gnu.org/software/gawk/manual/gawk.html#String-Functions

Numerical functions

atan2: arctangent of y / x in randians

cos: cosine of x in radians

exp: ex

int: floor float to int

log: natrual log

randn: (pseudo) random number between 0 and 1

sin: sine of x in radians

sqrt: square root

srand: (pseudo) random between 0 and 1, manually setting the seed

String functions

asort: array sort. Returns array with the values sorted

asori: array sort. Returns array with the keys (index) sorted

gensub: Search the target string target for matches of the regular expression regexp. Returns string with substituted text.

gsub: Search target for all of the longest, leftmost, nonoverlapping matching substrings it can find and replace them with replacement. Returns string with substituted text.

sub: Search target, which is treated as a string, for the leftmost, longest substring matched by the regular expression regexp. Returns string with substituted text.

index: Search the string in for the first occurrence of the string find. Returns the position where that occurence begins

length: returns length of string

match: Search string for the longest, leftmost substring matched by the regular expression regexp and return the character position (index) at which that substring begins.

split: Divide string into pieces delimted by field separator. Returns an array of strings

sprintf: Allows you to store the a string in the that would have been the output of printf into a variable

strtonum: Turn octal representation to number

substr: Substring starting at position x for length of y. Returns string

tolower: Lower-case the string

toupper: Upper-case the string

References

Trigonometric functions: https://en.wikipedia.org/wiki/Trigonometric_functions

Psuedo random number seed: https://en.wikipedia.org/wiki/Random_seed

Natural log to log 10: https://math.stackexchange.com/questions/107574/from-natural-log-to-log-base-10#107576